Table 1.
Physiological roles of PADs
| PAD isotype | Expression profile | Known substrates | Physiological roles | Refs |
|---|---|---|---|---|
| PAD1 | Immune cells, keratinocytes, hair follicle, epidermis, uterus | Keratin, Filaggrin, S100A3, MEK1-ERK1/2-MMP2 signalling enzymes | Skin differentiation, terminal differentiation of keratinocytes, epithelial-mesenchymal transition | [5, 28–30] |
| PAD2 | Immune cells, spleen, thymus, skeletal muscle, brain, glial cells, colon, kidney, pancreas, breast, epidermal, bone marrow, salivary gland, secretory gland, ear, eye | MPB, CXCL10, CXCL11, Vimentin, Actin, GFAP, S100A3, Histone H3, Histone H4 | Oligodendrocyte differentiation and myelination, brain plasticity, female reproduction, transcription regulation | [5, 29, 31–33] |
| PAD3 | Immune cells, keratinocytes, hair follicles, nerves | Filaggrin, Vimentin, Trichohyalin, S100A3 | Skin differentiation, hair follicle formation, terminal differentiation of keratinocytes | [5, 28, 29], |
| PAD4 |
Immune cells, brain, uterus, bone marrow, joints, cancerous tissues (e.g. breast carcinomas, lung carcinomas) |
NFC1, NCF2, S100A3, Collagen Type I, HAT p300, NPM1, GSK3β, ING4, RPS2, FUS, EWS,0 TAF15, ADAMTS13, Histone H1 (R54Cit), Histone H2A (R3Cit), Histone H3 (R17Cit, R26Cit, R2Cit, R8Cit), Histone H4 (R23Cit, R3Cit) | Immune cells differentiation, cellular differentiation, NET formation, gene expression regulation, tumorigenesis | [5, 13, 28, 29, 33–41] |
| PAD6 | Ovary, early embryo, testicles, ovum, oocyte, thymus | α-tubulin | Cytoskeletal reorganization in the egg and early embryo, preimplantation cleavage, early embryonic development, oocyte cytoskeletal sheet formation and female fertility | [42–44] |